1. Field of the Invention
The invention relates a capacitive touch device and sensing method thereof.
2. Description of the Related Art
In a current capacitive touch device, after sensing a capacitive touch panel, it is determined whether the touch panel is touched according to a sensing result to accordingly determine a touch position or a control gesture. To increase operating sensitivity, a sensing result is thoroughly inspected for distinguishing minute differences. However, it is possible that an actual operation environment of a capacitive touch device is filled with noises such that a satisfactory signal-to-noise ratio (SNR) can only be obtained to maintain the operation sensitivity by reinforcing signal strength or reducing noises.
For example, the signal strength is reinforced by boosting a driving voltage. Common noises form new electric fields with the capacitive touch device to produce undesirable effects. Source of electric fields include human static electricity, an LCD module, a power supply, a charger or household appliances. For example, approaches for reducing noises for maintaining a preferred SNR include synchronization, shielding, filter and grounding.
However, all of the above approaches for reinforcing signal strength or reducing noises need extra costs, and may also lead to a change in an overall structure and thus fail to meet a light and compact design.